This study will evaluate, in a controlled trial. the efficacy of a model Dual Diagnosis Treatment Program (DDTP) for schizophrenic patients who abuse stimulants. The new program, based on a stress-vulnerability-coping-competence conceptualization of schizophrenia and stimulant abuse, combines a highly structured and prescriptive model of social and independent skit training with assertive case management and long-term outpatient rehabilitation of both disorders in a single setting. The program components are arranged into modules which demonstrated promising results in a recent study in which substance-abusing and non-substance abusing schizophrenic patients served as subjects. These modules, which take into account the cognitive and attentional deficits commonly exhibited by persons who manifest these disorders, were specifically designed to prevent relapse of schizophrenic episodes and drug abuse while enhancing social performance and self-reliance. 130 stimulant abusing schizophrenics will be randomly assigned to either the DDTP or to other inpatient psychiatric units at the Brentwood Division, West Los Angeles VA Medical Center where they will receive customary care (CC). Initial assessment will include confirmation of schizophrenia and stimulant dependence, character and severity of psychopathology, and extent of recent drug use. Pretreatment, posttreatment, and follow-up assessments at 6, and 12 months will include current psychopathology, interim history of schizophrenia, current and recent substance use, psychosocial functioning, and adherence to treatment. In addition, psychopathology, drug use (confirmed by urine analysis) and stimulant craving will be assessed weekly during the first four months. This study will determine whether treatment in the new DDTP reduces stimulant abuse and psychopathology, while improving will functioning and treatment adherence. It will also identify pretreatment characteristics that may predict response to treatment. Finally the study will collect data on the temporal sequencing of stimulant abuse and exacerbations of the positive and negative symptoms of schizophrenia.